Generally, when an oil-in-water emulsification is conducted using oils including functional oils, an emulsification method wherein a lipophilic surfactant and a hydrophilic surfactant are used in combination so as to meet with the HLB required for materials to be emulsified has been applied. However, such a method requires highly-complicated and great effort to select surfactants optimum for the emulsification. Moreover, when various kinds of oils are present in combination, or when the blending ratio of oils such as silicone oil and polar oil is large, the emulsion stability is poor. Thus, it has been difficult to obtain an oil-in-water cosmetic with a good stability.
In contrast, it has already been reported that, the three-phase emulsification method wherein emulsification is carried out by adhering vesicle particles of an amphiphilic substance, which is present as an independent phase in an oil/amphiphilic substance/water system, to the surface of an oily base due to van der Waals' force provides much higher stability compared with conventional O/W emulsions (Patent Literature 1).
However, even in such a three-phase emulsification method, the emulsion stability was not satisfactory.
On the other hand, a lower alcohol is used by preference in various cosmetics because it provides the skin with a pleasant cooling sensation and a quick-drying feeling, and also it has astringent, cleansing, antiseptic properties as well as promoting effect on drying. When a large amount of lower alcohol is contained in an emulsified composition such as a milky lotion and a cream, a light feeling in use can be provided: however, hardness or viscosity of the system was generally lowered and the emulsion stability tended to become poor.